What is stereology?

Unbiased stereology is recognized in biological research as the best-practice method for quantitative histology. It is used to accurately quantify the number of cells, the length of fibers, and the area and volume of biological structures or regions. Stereology plays an important role in validating and rejecting experimental hypotheses in biological research. It is often used to help answer questions such as:

Is the number of cells in a region of interest in experimental subjects different than controls?

Has the length of nerve fibers or blood vessels changed?

Has there been a change in volume of a region of interest?

How much of my region of interest has been damaged by an injury?

Data and analyses obtained using stereology are more accurate than ad hoc quantitative analyses. Unbiased stereology uses systematic random sampling (a statistical sampling method) to unbiasedly select a representative sample of the region of interest. Then, researchers use a set of rigorously tested rules to mark cells and structures in each sampling site for quantification. Other techniques for obtaining quantitative analyses of cell populations, such as counting cell profiles at the top of each physical section, or using automated cell detection algorithms, yield inaccurate and biased results. To learn more about sources of biases when quantifying cell populations, please use the following resources:

This presentation contains more information about the theory of stereology

By using unbiased stereology, researchers get unbiased, accurate and reliable data. For this reason, many peer-reviewed journals require or recommend the use of unbiased stereology when quantifying cells or structures. The Stereo Investigator system for unbiased stereology has been cited in over 4,000 published papers, making it by far the most-cited unbiased stereology system in the world.

In order to obtain the accurate results that unbiased stereology is known for, it is important to follow certain practices, described in the literature, during tissue preparation. MBF has Ph.D. staff scientists who can give you practical support for all aspects of stereologic experimental design—from the tissue processing stage all the way to interpreting the results.

Additionally, MBF provides you with a host of expert stereological support that includes detailed software workflows within Stereo Investigator, extensive on-line documentation, videos and webinars. All of this is available to help guide you through the steps of a stereological study that are briefly outlined below.

1) Sample. Systematic random sampling (SRS) is an unbiased and efficient way to select sample sites within the region of interest. Stereo Investigator uses systematic random sampling (SRS) to obtain a representative sample of the tissue. The system first chooses a random starting site within the region of interest - a crucial step for SRS - then directs the motorized XY stage to automatically move at a constant interval to the subsequent sample sites.

2) Measure. Cells or structures in the chosen sampling sites are counted or measured with probes – graphical shapes superimposed on the specimen. Stereo Investigator includes workflows for all of the most popular probes, along with detailed documentation that will guide you through any of the 30+ probes in the program. Stereo Investigator guides you to use the specific stereological rules to follow for each probe to ensure that you make accurate measurements.

3) Results. The probe results are calculated to provide an accurate estimate of the counts or measurements for the region(s) of interest as a whole. Stereo Investigator automatically calculates the results for you. The accuracy of the data is also calculated and provided as the coefficient of error. Stereo Investigator also exports results directly into Microsoft Excel so you can easily sort and further analyze the data.